The field of this invention relates to a stuffing box which is used in connection with an oil well pumping system. The stuffing box is utilized at the top of the oil well pumping system and is designed to prevent leakage of the oil that is being pumped exteriorly of the oil well pumping system.
Oil wells are produced by using drilling rig. After the well is obtained, the drilling rig is removed and a wellhead of a pumping system is installed at the ground whose purpose is to pump the oil from the oil well. Pumped oil is caused to flow through a storage reservoir after being removed from the well.
Within the wellhead there is utilized a rod which is lineally moved in a reciprocating manner which is part of the pumping operation. This rod, called a polish rod, extends from the wellhead into the ambient. There has to be a seal between this rod and the wellhead so that the pumped crude oil will not flow uncontrollably from the wellhead to be deposited on the ground around the wellhead. Not only is this oil lost (not usable) but also environmental laws prevent such contamination of the environment. Also, accumulation of oil around a wellhead results in an exceedingly unsightly appearance.
In the past, what has been utilized to provide the seal between the polish rod and the wellhead is referred to as a stuffing box. To make a stuffing box preventing leakage of oil from the wellhead is difficult because the polish rod is continuously moving relative to the stuffing box and wear is a constant problem. This wear results in leakage. Generally, it only takes a few days of operation of the polish rod for leakage to occur.
It is common for the stuffing box to utilize the crude oil itself as the lubricant to decrease the friction involved in moving of the polish rod in the stuffing box. However, this crude oil inherently obtains a substantial amount of contaminants and these contaminants are abrasive. Therefore, this type of lubrication of the polish rod is at best, poor.